CN115701674A

CN115701674A - Dual-polarized radiation unit for antenna, antenna and antenna system

Info

Publication number: CN115701674A
Application number: CN202110880669.4A
Authority: CN
Inventors: H·普里亚南达; 胡中皓; J·德西亚; D·达马维里亚
Original assignee: Prologis Communication Technology Suzhou Co Ltd
Current assignee: Prologis Communication Technology Suzhou Co Ltd
Priority date: 2021-08-02
Filing date: 2021-08-02
Publication date: 2023-02-10
Also published as: WO2023010829A1; EP4383455A1; US20240178564A1

Abstract

The present disclosure relates to a dual polarized radiation element for an antenna, an antenna and an antenna system. Wherein, the dual polarized radiation unit for antenna according to the present disclosure includes: four dipoles, wherein radiating arms of the four dipoles are planar structures and are symmetrical about two mutually perpendicular axes, wherein the two mutually perpendicular lines divide the radiating element equally into four regions, and central portions of the four regions are in direct current conduction, and wherein each of the four regions has a hollow region.

Description

Dual-polarized radiation unit for antenna, antenna and antenna system

Technical Field

The present disclosure relates to the field of radio frequency communication technologies, and in particular, to a dual-polarized radiation unit for an antenna, an antenna including the dual-polarized radiation unit for an antenna, and an antenna system including the antenna.

Background

These spectral ranges are allocated to telecommunications for communication in a broad spectrum between 400MHz and 6GHz, the so-called sub-6 GHz bands. However, it is not technically possible to design analog components such as filters, phase shifters, radiating elements, and amplifiers for such wide bandwidths. Therefore, the frequency band below 6GHz can be further divided into a plurality of sub-frequency bands and independently operated, so as to realize the design of the analog component. For example, the industry typically divides the frequency bands below 6GHz into the following four separate operating sub-bands: 600MHz to 1GHz, 1.4GHz to 3GHz, 3GHz to 4.2GHz and 5GHz-6GHz. A base station antenna for LTE, 5G or 3G communication is composed of a plurality of radiating element arrays working at different frequency bands.

These separate frequency bands require separate components such as filters, phase shifters, amplifiers, radiating elements. All these components cannot interfere with each other, the isolation needs to be around 20dB at minimum, and the isolation between each signal path is preferably 30dB. This is relatively easy to achieve for shielded channels such as filters, phase shifters, etc., where all signals are shielded by microstrip or stripline. However, since the radiation unit radiates into the air and is very easily coupled, it is relatively difficult to isolate the radiation unit. If the isolation cannot reach this level, there will be severe pattern distortion and inter-port isolation problems. These problems will degrade network performance. Isolation may be enhanced if the radiating elements are separated by more than the two lowest frequencies, but such separation will reduce the integration of the antenna system and increase the volume of the antenna system.

On the other hand, the space for installing antennas on the base station tower is very limited, since it needs to cover multiple frequency bands, operators and sectors. In the last five to seven years, the industry is moving towards combining multiple sub-band systems into the same antenna cover or product, making isolation a challenge.

Disclosure of Invention

As mentioned above, there are technical problems in the prior art that interference may be formed between the existing radiation units of different frequency bands, and due to the existence of the interference problem between the low frequency radiation unit and the high frequency radiation unit, a fixed positional relationship exists between the low frequency radiation unit and the high frequency radiation unit, and mutual decoupling cannot be achieved, thereby limiting the design of the multiband radiation unit.

In order to solve the above technical problem, the inventor of the present disclosure has proposed, based on the above thought, a dual polarized radiation unit for an antenna, the dual polarized radiation unit including: four dipoles, wherein radiating arms of the four dipoles are planar structures and are symmetrical about two mutually perpendicular axes, wherein the two mutually perpendicular lines divide the radiating element equally into four regions, and central portions of the four regions are in direct current conduction, and wherein each of the four regions has a hollow region.

The dual-polarized radiation unit provided by the present disclosure has a hollow area, so that the interference of the dual-polarized radiation unit with electromagnetic wave signals generated by the radiation units for other frequency bands can be reduced, and the dual-polarized radiation unit provided by the present disclosure is more friendly to system integration, and the radiation performance of the multi-band radiation unit generated by integration is better than that of the radiation unit in the prior art. In addition, the dual-polarized radiation unit proposed according to the present disclosure has a simple and convenient manufacturing process because its central portion is dc-conducted, and has a better product uniformity and radiation performance because it can be integrally constructed.

In one embodiment according to the present disclosure, a first edge of the dual polarized radiating element is perpendicular to a corresponding line of the two mutually perpendicular lines, wherein the first edge is an edge crossing the corresponding line. In a conventional dual-polarized radiating element, two mutually perpendicular lines of the radiating element are generally diagonal lines, that is, an edge of the dual-polarized radiating element to which the diagonal lines extend is generally a corner, not an edge, of the dual-polarized radiating element. An edge of the dual-polarized radiation element to which two mutually perpendicular lines of the dual-polarized radiation element extend is an edge of the dual-polarized radiation element, and the edge is perpendicular to a corresponding line of the two mutually perpendicular lines. In a geometric sense, compared with the conventional dual-polarized radiation unit, the dual-polarized radiation unit according to the present disclosure adopts a corner-cut processing manner, so that the area of the dual-polarized radiation unit provided according to the present disclosure is smaller than that of the conventional dual-polarized radiation unit, thereby saving more materials and further reducing the manufacturing cost.

Preferably, in one embodiment according to the present disclosure, the dual polarized radiating element has an octagonal shape. Compared to a conventional dual-polarized radiation element having a shape of, for example, a quadrilateral, the dual-polarized radiation element according to the present disclosure takes a corner-cut approach, so that the dual-polarized radiation element proposed according to the present disclosure has, for example, an octagonal shape. Compared with the traditional dual-polarized radiating unit, the area of the radiating unit is smaller, so that more materials are saved, and the manufacturing cost is reduced.

In an embodiment according to the present disclosure, the dual polarized radiating element further includes: four slits, which are respectively located at the adjoining positions of two adjacent regions of the four regions. Two of the four slits point in one polarization direction, for example a polarization direction of +45 °, and two other slits point in another polarization direction, for example a polarization direction of-45 °. Although the size of the slot, for example, the length of the slot, is reduced by the chamfering process such as the above-mentioned process, the resonant frequency of the current loop can be moved higher until the resonance exceeds the operating range of the antenna, thereby being able to reduce the influence of other frequency bands on the dual-polarized radiating element proposed according to the present disclosure.

In an embodiment according to the present disclosure, the dual polarized radiating element further includes: four feed lines associated with the four slots, and each of the four feed lines extending from a middle region of the dual-polarized radiating element to a feed point of the slot associated therewith, wherein a length of the feed lines is associated with a matching impedance.

Preferably, in an embodiment according to the present disclosure, the dual polarized radiation unit further includes: a common mode choke circuit configured to be disposed near the feed point and associated with one of the four slots. Further preferably, in one embodiment according to the present disclosure, the common mode choke circuit further includes a first track and a second track, wherein the first track and the second track are configured in parallel to each other on both sides of the radiation arm in the form of an inductance coil, and wherein electrical lengths of the first track and the second track are equal and coil winding directions of the first track and the second track are identical.

Alternatively or additionally, in an embodiment according to the present disclosure, the dual polarized radiating element further comprises: a shunt filter configured as a wire extending inward from an edge of the hollow region. Preferably, in one embodiment according to the present disclosure, the parallel filter is configured as an open line.

In one embodiment according to the present disclosure, the dual polarized radiating element further comprises: an inductive element extending from an edge of the hollow region away from a central region of the dual polarized radiating elements towards the central region.

Furthermore, a second aspect of the present disclosure proposes an antenna comprising: at least one dual polarized radiating element according to the first aspect of the present disclosure; and a radiating element matching circuit.

Furthermore, a third aspect of the present disclosure proposes an antenna system, which includes: an antenna according to the second aspect of the present disclosure; and at least one second antenna, wherein the operating frequency band of the at least one second antenna is higher than the operating frequency band of the antenna.

In one embodiment according to the present disclosure, the antennas are staggered from the second antenna. Optionally, in an embodiment according to the present disclosure, the number of columns of the antennas is equal to the number of columns of the second antennas, or the number of columns of the second antennas is twice the number of columns of the antennas.

In summary, the dual-polarized radiation unit proposed by the present disclosure has a hollow area, so that the interference to the electromagnetic wave signals generated by the radiation units for other frequency bands can be reduced, and the dual-polarized radiation unit proposed by the present disclosure is more friendly to system integration, and the radiation performance of the multi-band radiation unit generated by integration is better than that of the radiation unit in the prior art. In addition, the dual-polarized radiation unit proposed according to the present disclosure has a simple and convenient manufacturing process because its central portion is dc-conducted, and has a better product uniformity and radiation performance because it can be integrally constructed.

Drawings

The features, advantages and other aspects of various embodiments of the present disclosure will become more apparent by referring to the following detailed description in conjunction with the accompanying drawings, in which several embodiments of the present disclosure are shown by way of illustration and not limitation, wherein:

fig. 1A shows a perspective view of an antenna system 100 comprising dual polarized radiating elements 110 and high frequency radiating elements 120 according to one embodiment of the prior art;

fig. 1B shows a side view of an antenna system 100 comprising dual polarized radiating elements 110 and high frequency radiating elements 120 according to one embodiment of the prior art;

fig. 2A shows a schematic diagram of a dual polarized radiating element 210 for an antenna according to one embodiment of the present disclosure;

fig. 2B shows a partially enlarged schematic diagram of a common mode choke circuit of the dual polarized radiating element 210 for an antenna according to one embodiment of the present disclosure;

fig. 2C shows a side view of a dual polarized radiating element 210 for an antenna according to one embodiment of the present disclosure;

fig. 2D illustrates a side perspective view of a dual polarized radiating element 210 for an antenna according to one embodiment of the present disclosure;

fig. 2E illustrates a bottom perspective view of a dual polarized radiating element 210 for an antenna according to one embodiment of the present disclosure;

fig. 2F shows an exploded view of a dual polarized radiation element 210 for an antenna according to one embodiment of the present disclosure;

fig. 3 shows a schematic diagram of an antenna system 300 according to an embodiment of the present disclosure;

fig. 4A shows a schematic diagram of an antenna system 400A according to another embodiment of the present disclosure; and

fig. 4B shows a schematic diagram of an antenna system 400B according to another embodiment of the present disclosure.

Detailed Description

Various exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. Although the example methods, apparatus, and devices described below include software and/or firmware executed on hardware among other components, it should be noted that these examples are merely illustrative and should not be considered as limiting. For example, it is contemplated that any or all of the hardware, software, and firmware components could be embodied exclusively in hardware, exclusively in software, or in any combination of hardware and software. Thus, while the following describes example methods and apparatus, persons of ordinary skill in the art will readily appreciate that the examples provided are not intended to limit the manner in which the methods and apparatus may be implemented.

Furthermore, the flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of methods and systems according to various embodiments of the present disclosure. It should be noted that the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

As described above, there is a technical problem in the prior art that interference is generated between the existing radiating elements in different frequency bands. It is an object of the present invention to provide a dual polarized low band radiating element or element operating below 1GHz which, even if two or three different elements overlap to a large extent (height in different dimensions), is able to isolate the other high band interference (sub-bands 2, 3, 4 as described above) well, so that the high frequency pattern remains unchanged, as if there were no low band elements on top. Furthermore, the performance (e.g. radiation pattern and return loss) impact on the low band element itself is minimized.

WO2015/124573A discloses a similar form of radiating element. Fig. 1A shows a perspective view of an antenna system 100 including dual-polarized radiation elements 110 and high-frequency radiation elements 120 according to an embodiment of the related art, and fig. 1B shows a side view of the antenna system 100 including dual-polarized radiation elements 110 and high-frequency radiation elements 120 according to an embodiment of the related art. As can be seen from the two drawings of fig. 1, WO2015/124573A discloses an antenna system 100 that outlines a low-band radiating element 110 constructed using a four-slot feed method. It further outlines a method of obtaining a multi-band antenna system 100 by placing the high-band radiating element 120 on top of the low-band element 110 and using an additional metal sheet 130 as a reflector for the high-band element 120. Thus, the high band array 120 will be in line with the low band array 110, with half of the high frequency elements 120 on top of the low frequency elements 110 and the other half of the high frequency elements 120 between the low frequency elements 110. In such a design of the radiation elements 110 and the radiation elements 120 of the antenna system 100, the designer does not attempt to make the high-band radiation elements 120 invisible to the low-band radiation elements 110, but arranges the high-band radiation elements 120 in such a way that the low-band radiation elements 110 do not obscure the high-band radiation elements 120. However, this method has some disadvantages:

first, the vertical cell pitch of the radiation elements 120 of the high band array is limited to half the pitch of the radiation elements 110 of the low band array. The spacing of the radiating elements 110 of the low band array is typically about 0.7 λ, and reasonable grating lobe levels can be achieved at larger down-tilt angles, where the grating lobe is a side lobe that increases with the angle of the scanned beam, in direct proportion to the ratio of the spacing between the radiating elements to the wavelength of the radiating elements of the array. A larger spacing between radiating elements results in a higher grating lobe. The grating lobes reduce the gain of the radiating elements of the array and cannot be reduced by adjusting the amplitude or phase taper of the radiating elements of the array.

Second, since the high frequencies are spectrally broader, they are more sensitive to grating lobe effects at higher frequencies within the band. The spacing between the radiating elements is in practice used in industry at 0.78 lambda to 0.85 lambda. If the spacing between the radiating elements of the high frequency band is half the spacing between the radiating elements of the low frequency band, it is greater than 0.9 λ for high frequencies, resulting in significant grating lobes. The grating lobe of the radiating element of the 0.78 lambda array tilted 10 degrees downward is about 13.5dB, while the grating lobe of the radiating element of the 0.91 lambda array tilted 10 degrees downward is about 7.5dB.

In view of the above problems, the inventors of the present disclosure have innovated a method of improving the grating lobes of the radiation elements of the high-band, i.e., allowing the spacing between the radiation elements of the high-band array to be free (typically less than 0.7 wavelength). This can only be achieved by placing the radiating elements of the high band array side by side with the radiating elements of the low band array. However, since the radiating elements of the conventional low-band element are not hidden at the high-band frequencies, if the radiating elements of the high-band array are very close to the radiating elements of the low-band array, the pattern of the high-band may be severely distorted.

To achieve good high frequency vertical and horizontal plane pattern performance with conventional low band array radiating elements, the high band array radiating elements must be placed side-by-side with and at a large distance from the low band array radiating elements. This limits the possibility of having multiple radiating elements of the high band array and radiating elements of the low band array in a narrow width antenna.

In designs according to the present disclosure, the radiating elements of the low band array are not visible to high band frequencies, which provides flexibility in placing the radiating elements of the high band array interleaved with the radiating elements of the low band array. Furthermore, there is no limit to the spacing between radiating elements of the high-band array, which provides freedom to obtain optimal grating lobe and gain performance.

The dual-polarized radiation element 210 proposed according to the present disclosure is described below with reference to fig. 2A and 2B, where fig. 2A shows a schematic diagram of the dual-polarized radiation element 210 for an antenna according to an embodiment of the present disclosure, fig. 2B shows a partially enlarged schematic diagram of a common mode choke circuit of the dual-polarized radiation element 210 for an antenna according to an embodiment of the present disclosure, and fig. 2C shows a side view of the dual-polarized radiation element 210 for an antenna according to an embodiment of the present disclosure. As can be seen in fig. 2A: the dual-polarized radiation element 210 for an antenna proposed according to the present disclosure includes four dipoles, i.e., one diagonal line in fig. 2A forms a pair of dipoles, for example, two poles along one end of the diagonal line 211 form a dipole, two dipoles at both ends of the diagonal line 211 form a pair of dipoles, two poles along one end of the diagonal line 213 form a dipole, and two dipoles at both ends of the diagonal line 213 form a pair of dipoles. In other words, the four dipoles together form two pairs of dipoles along two

diagonal lines

211 and 213, wherein the radiating arms (i.e., the most outward-extending gray regions in the drawing) of the four dipoles are in a planar structure and are axisymmetric with respect to two mutually

perpendicular lines

211 and 213, wherein the two mutually

perpendicular lines

211 and 213 equally divide the dual-polarized radiating unit 210 into four regions, and the central portions of the four regions are dc-conductive, i.e., the four regions are dc-conductive at the crossing regions of the two

diagonal lines

211 and 213, rather than being hollow and unconnected, and wherein each of the four regions has a hollow region. That is, the two

diagonal lines

211 and 213 divide the dual-polarized radiation unit 210 into each area, and the middle of each area has a hollow area which is blank in the figure. Since the dual-polarized radiation unit 210 is provided with the hollow region, high-frequency signals are allowed to pass through, and the dual-polarized radiation unit 210 shields low-frequency oscillators, so that diffraction is reduced to the maximum extent. In other words, the dual polarized (e.g., +45 °, -45 °) radiating elements 210 operating in the low frequency band (sub-band 1) are designed to be invisible to the high frequency radiating elements operating in the high frequency band (sub-bands 2, 3, 4). The dual-polarized radiating element 210 has inherently good radiating performance at the return loss bandwidth on sub-band 1. In addition, the dual-polarized radiating element 210 can be implemented by a PCB, for example, but can also be formed by a metal plate or a die-cast plate, because the main body of the low-band dual-polarized radiating element 210 is dc-connected, which means that the low-band dual-polarized radiating element 210 can be integrally formed by metal casting or sheet metal processing.

In fig. 2, the dielectric plate is missing, i.e. microstrip transmission line 214 and microstrip transmission line 216 are shown lying on one plane, while plane 223, in which the dipoles represented by the gray areas lie, is above the other plane, which planes may be parallel to each other, and the dielectric plate may be located, for example, between these two parallel planes.

The dual-polarized radiation unit 210 according to the present disclosure has a simple and convenient manufacturing process because its central portion is dc-connected, and the dual-polarized radiation unit 210 according to the present disclosure has a better product uniformity and radiation performance because it can be integrally constructed. In addition, the dual-polarized radiation unit 210 proposed according to the present disclosure has a hollow area, so that the interference of the dual-polarized radiation unit 210 with the electromagnetic wave signals generated by the radiation units for other frequency bands can be reduced, and thus the dual-polarized radiation unit 210 proposed according to the present disclosure is more friendly to system integration, and the radiation performance of the multi-band radiation unit generated by integration is better than that of the radiation unit in the prior art. The size of the slot 212 is reduced by approximately 1/4 of the high frequency wavelength compared to conventional designs, for example by edge chamfering. When a high-band radiating element is blocked by a low-band radiating element (e.g., here dual-polarized radiating element 210), a current loop for high-band frequencies is established at the slot 212 and at the edges of the slot 212. By reducing the size of the slot 212, such as a slot, the resonant frequency of the current loop can be moved higher until the resonance is outside the operating range of the antenna. Despite the reduction in slot size, other features of the geometry were adjusted to maintain the impedance bandwidth at low band frequencies (return loss better than 12 dB).

As can be seen from fig. 2A: a first side (e.g., 211a or 211 b) of the dual polarized radiating element 210 is perpendicular to a corresponding line (e.g., diagonal 211) of the two mutually perpendicular lines; and the other side (e.g., 213a or 213 b) of the dual-polarized radiation element 210 is perpendicular to the other corresponding line (e.g., diagonal line 213) of the two mutually perpendicular lines, wherein the first side (e.g., 211a or 211 b) is the side crossing the corresponding line (e.g., diagonal line 211). In a conventional dual-polarized radiation element 110, two mutually perpendicular lines thereof are generally diagonal lines, that is, an edge of the dual-polarized radiation element 110 to which the diagonal lines extend is generally a corner, not an edge, of the dual-polarized radiation element 110. An edge of the dual-polarized radiation element 210 to which the two mutually

perpendicular lines

211 and 213 of the dual-polarized radiation element 210 according to the present disclosure extend is an edge of the dual-polarized radiation element 210, and the edge is perpendicular to a corresponding line of the two mutually

perpendicular lines

211 and 213. In a manner of representation, compared to the conventional dual-polarized radiation unit 110, the dual-polarized radiation unit 210 according to the present disclosure adopts a corner-cut processing manner, so that the area of the dual-polarized radiation unit 210 proposed according to the present disclosure is smaller than that of the conventional dual-polarized radiation unit 110, thereby saving more materials and further reducing the manufacturing cost. Preferably, as shown in fig. 2A, the dual polarized radiation element 210 has an octagonal shape.

Specifically, the structure of the radiation unit 210 is composed of a conductive plate having four slots 212 on

diagonal lines

211 and 213. Each slot 212 is in the form of a slot, wherein two slots on diagonal 213 point to a +45 ° vector and two slots on diagonal 211 point to a-45 ° vector, the two polarizations together constituting the desired polarization direction of the dual-polarized radiating element 210. As shown in fig. 2A, each slot is fed at the other slot using one microstrip transmission line 214 combined with a corresponding microstrip transmission line 216 to the polarization of the antenna. In the embodiment shown in fig. 2A, the feed point to which the microstrip transmission line 214 is connected would produce +45 ° polarized radiation when viewed from the top, while the feed point to which the microstrip transmission line 216 is connected would produce-45 ° polarized radiation. The location of the feed point along slot 212 determines the impedance of the feed point, which can be matched to 50 ohms using an impedance transformation line and a power splitter. The two slots of each polarization are fed with equal amplitude and phase. The support structure is shown in fig. 2C. The current design is made of 2

interdigitated PCBs

215 and 222, each

PCB

215 and 222 being fed with polarization through a power splitter. The output of the power divider is connected to the microstrip line on the radiating element 210. The feed structure includes an equipower splitter and a cutoff impedance transformation line that can be matched, for example, to 50 ohms, or in other embodiments to 75 ohms or other values as desired for a particular application. These are realized by microstrip circuits, where the back of the feed structure also acts as a balun for the radiating element. The feeding structure and the radiating element do not have to use a PCB, but alternative versions may be implemented using metal plates or die-cast metal.

In summary, the dual-polarized radiating element 210 comprises four slots 212, the four slots 212 being located at respective abutments of two adjacent ones of the four regions. Two of the four slits 212 (two slits on the same diagonal) point in one polarization direction, for example, a polarization direction of +45 °, and the other two slits (two slits on the other diagonal) point in the other polarization direction, for example, a polarization direction of-45 °. Although the size of the slot, for example, the length of the slot, is reduced by the chamfering process such as the foregoing, the resonant frequency of the current loop can be moved higher until the resonance exceeds the operating range of the antenna, thereby being able to reduce the influence of other frequency bands on the dual-polarized radiation unit proposed according to the present disclosure. Preferably, the dual-polarized radiation element 210 comprises four

feed lines

214 and 216, the four

feed lines

214 and 216 being associated with the four slots 212, and each of the four

feed lines

214 and 216 extending from a middle area (e.g. an area where two

diagonal lines

211 and 213 intersect) of the dual-polarized radiation element 210 to a feed point of the slot 212 associated therewith, wherein the length of the

feed lines

214 and 216 is associated with a matching impedance.

As can also be seen from fig. 2A, the dual-polarized radiating element 210 further includes a common mode choke circuit 218, and the common mode choke circuit 218 is configured to be disposed near the feeding point and associated with one of the four slots. Alternatively or additionally, the dual polarized radiating element 210 further comprises parallel filters 219, the parallel filters 219 being configured as wires extending inwards from the edges of the hollow area, preferably the parallel filters 219 being configured as symmetrical structures. A parallel filter 219 is added to the hollow region with the inside hollowed out. The parallel filter 219 is connected to the body of the dual-polarized radiating element 210, generating impedance disturbances at the connection locations. The frequency at which the impedance disturbance occurs is controlled by the electrical length of the parallel filter 219, which typically has an electrical length greater than λ/6 and equal to or less than λ/4, the parallel filter 219 acting as a band reject filter. The position of the parallel filter 219 is optimized to suppress local high frequency band currents flowing around the hollow region of the hollow core. The parallel filter 219 acts as a parallel circuit as the lines of the parallel filter 219 are added to the continuous conductive track. Further preferably, the parallel filter 219 is configured as an open line.

Furthermore, optionally, the dual-polarized radiation element 210 further comprises an inductive element 217, the inductive element 217 extending from an edge (e.g. an outer edge) of the hollow area away from a central area of the dual-polarized radiation element 210 towards the central area. A high impedance portion is created at the outer edge. As the size of the diagonal slots 212 is reduced, the resonant frequency of the low frequency radiating elements (e.g., dual polarized radiating elements 210) will oscillate to a higher frequency than the frequency of the designed low band center of operation. To rebalance the resonant frequency of the lower band, a reactive part 217 is added. Although the diagonal dimension is smaller than the ideal dimension, this function increases the electrical length of the radiating element.

Here, although only one open parallel filter 219 and one inductive element 217 are labeled, it will be appreciated by those skilled in the art that each hollow region may have one open parallel filter 219 and one inductive element 217.

Also, fig. 2B shows a partially enlarged schematic diagram of the common mode choke circuit 218 of the dual polarized radiating element 210 for an antenna according to an embodiment of the present disclosure. As can be seen from fig. 2B: preferably, the common mode choke circuit 218 further includes a first track 2181 and a second track 2182, wherein the first track 2181 and the second track 2182 are connected to the radiation arm in parallel to each other in the form of an inductance coil and the coils of the first track 2181 and the second track 2182 are wound in the same direction, and since they are configured at both sides of the radiation arm, a plurality of via holes, i.e., via holes 2183 shown in fig. 2B, are present on the radiation arm, and wherein the first track 2181 and the second track 2182 are equal in electrical length. A common mode choke circuit 218, such as a common mode choke, is implemented on the balun, as shown in fig. 2B. High band frequencies in the range of 1.4GHz to 2.7GHz set the common mode at the balun of the low band. The low band current of this region is differential, so the common mode choke circuit 218 is used to reject the high band current without adversely affecting the low band rejection. Fig. 2B shows a close-up of the structure. Two

conductive tracks

2181 and 2182 circulate in parallel with each other on two layers of the PCB. The two rails act as coupled inductors. When a common mode current passes through the structure, the magnetic flux generated by each branch adds up, thereby generating a large inductance. The differential currents produce magnetic fluxes that cancel each other out so that the inductance seen by the differential mode is very small. Thus, high-frequency band currents are effectively choked while passing low-frequency band currents are relatively unaffected. The common mode filter circuit 218 should be wound as tightly as possible on the upper and lower layers of chokes to increase the common mode choke effect and the differential conduction mechanism. The common mode choke circuit 218 has a length of at least 1/8 wavelength of a high frequency. When the length is longer, the choking effect is more obvious.

To more visually illustrate the dual polarized radiating element 210 according to the present disclosure. Wherein fig. 2D illustrates a side perspective view of the dual-polarized radiation unit 210 for an antenna according to one embodiment of the present disclosure, fig. 2E illustrates a bottom perspective view of the dual-polarized radiation unit 210 for an antenna according to one embodiment of the present disclosure, and fig. 2F illustrates an exploded view of the dual-polarized radiation unit 210 for an antenna according to one embodiment of the present disclosure.

As can be seen from fig. 2D, the microstrip transmission line 214 and the microstrip transmission line 216 and the common mode choke circuit 218 can be located, for example, on one side of a dielectric board 221, which dielectric board 221 can be supported by two

PCB circuit boards

215 and 222. As can be seen from fig. 2E, the plane 223 in which the dipoles are located can be located on the other side of the dielectric plate 221, for example. As can be seen in fig. 2F, the common mode choke circuit 218 comprises a first track 2181 and a second track 2182 located on two different planes, wherein the first track 2181 can be located in the plane 223 in which the dipoles are located, for example, and the second track 2182 can be located in the plane in which the microstrip transmission line 214 and the microstrip transmission line 216 are located, for example, the two

tracks

2181 and 2182 being connected by a via passing through the dielectric plate 221. The two

tracks

2181 and 2182 can be connected to the radiating arm in the form of an inductive coil, for example, and the direction of the coils of the first and

second tracks

2181 and 2182 are coincident and the first and

second tracks

2181 and 2182 are equal in electrical length.

Furthermore, a second aspect of the present disclosure proposes an antenna comprising at least one dual polarized radiation element 210 according to the above illustrated fig. 2A, 2B or 2C and a radiation element matching circuit. Since the dual-polarized radiating elements 210 proposed according to the present disclosure do not have to overlap with radiating elements of other frequency bands, the height d of the multiband antenna system formed by the dual-polarized radiating elements according to the present disclosure can be significantly smaller than that of the multiband antenna system formed according to the prior art.

Still further, a third aspect of the present disclosure proposes an antenna system including: an antenna according to the second aspect of the present disclosure; and at least one second antenna, wherein the operating frequency band of the at least one second antenna is higher than the operating frequency band of the antenna. Preferably, the antennas are staggered from the second antenna. The antenna system proposed according to the present disclosure is described below with the aid of fig. 3. Fig. 3 shows a schematic diagram of an antenna system 300 according to one embodiment of the present disclosure. As can be seen from fig. 3, the antenna system 300 proposed according to the present disclosure comprises at least antennas for radiating radio frequency signals of two different frequency bands, wherein, for example, the first antenna 310 is configured for radiating signals of frequency band 1, i.e. the first antenna 310 is configured as a low frequency antenna; correspondingly, the second antenna 320 is designed, for example, for radiating signals in the frequency range 2, 3 or 4, i.e., the second antenna 320 is designed as a high-frequency antenna. Here, the first antenna 310 and the second antenna 320 are arranged in a staggered manner, that is, for example, one column of the low frequency antenna 310 is arranged, then two columns of the high frequency antenna 320 are arranged, then one column of the low frequency antenna 310 is arranged, and so on. Preferably, the first antenna 310 at least partially covers the second antenna 320 to reduce the distance between two adjacent columns of high frequency antennas 320.

Optionally, in an embodiment according to the present disclosure, the number of columns of the antennas is equal to the number of columns of the second antennas, or the number of columns of the second antennas is twice the number of columns of the antennas. The construction of a multiband antenna system by means of dual polarized radiating elements 210 according to the present disclosure is described below by means of fig. 4A and 4B. Fig. 4A shows a schematic diagram of an antenna system 400A according to another embodiment of the present disclosure, and fig. 4B shows a schematic diagram of an antenna system 400B according to another embodiment of the present disclosure.

As can be seen from fig. 4A, the antenna system 400a according to the present disclosure includes two columns of low frequency antennas 410a and two columns of high frequency antennas 420a, that is, the number of columns of the low frequency antennas 410a is equal to the number of columns of the high frequency antennas 420 a; in contrast, as can be seen from fig. 4B, the antenna system 400B according to the present disclosure includes two columns of low frequency antennas 410B and four columns of high frequency antennas 420B, that is, the number of columns of the low frequency antennas 410a and the number of columns of the high frequency antennas 420a are not equal, and the number of columns of the high frequency antennas 420B is twice the number of columns of the low frequency antennas 420 a. Preferably, the low frequency antenna 410b at least partially covers two columns of high frequency antennas 420b to reduce the distance between two adjacent columns of high frequency antennas 420 b.

In a compact multiband antenna, the radiating elements of the low band array and the radiating elements of the high band array are placed in close proximity, causing the radiating elements of the low band array to partially obstruct the radiating elements of the high band array. Therefore, if the radiation elements of the low band array are not designed to be transparent to the high band, distortion of the radiation pattern of the high band may be caused. Distortion is the result of two mechanisms: diffraction and resonance. Diffraction occurs when electromagnetic waves interact with obstacles causing the waves to distort around the object. In this case, if the radiating element of the low band array is a continuous piece of metal, it causes a higher degree of diffraction. Diffraction occurring in the near field of the radiating element results in significant distortion of the far field pattern.

When the radiation of the high frequency band excites the radiation elements of the low frequency band array, the radiation elements of the low frequency band array locally resonate in the high frequency band. The current is sensitive to the geometry of the local structure in terms of electrical length and impedance. These currents themselves can cause unwanted radiation and thus distortion of the high-band far-field pattern.

The radiating elements of the low band array according to the present invention employ various means to address the above distortion mechanism. To minimize diffraction, the radiating elements of the low band array have a hollow in the structure that allows the high band energy to pass through (the maximum size of the hollow should be greater than 1/2 wavelength). The low band radiating elements according to the present disclosure, such as dipole radiating elements according to the present disclosure, are chamfered at four corners, resulting in less shadowing of the high band array by the low band radiating elements, as compared to conventional radiating elements.

To solve the resonance problem, the following methods are used. High impedance points are introduced at certain locations of the low band radiating element geometry to suppress high band resonances. The high impedance is frequency selective and is tuned to suppress high band currents while not adversely affecting low band currents. The common mode choke coil is used for inhibiting high-frequency band common mode resonance at certain positions of the low-frequency band radiating unit. The first is a common mode filter used on low frequency oscillators. The filter is composed of two tightly wound inductors in the same direction, and a high reactance is manufactured at a high frequency, and the resistance value of the high reactance is used for reducing high-frequency resonance generated on a low-frequency oscillator. But also to conduct differential low frequency currents. The filter circuit is longer than the choke frequency by 1/8 wavelength. The longer the effect is more obvious. The second type is a filter formed by high-frequency 1/4 wavelength impedance lines connected in parallel to a low-frequency oscillator. The low-frequency oscillator with the hollow-out characteristics and the characteristics of the two filter circuits can reduce diffraction on the high-frequency oscillator.

In summary, the dual-polarized radiation element 210 proposed according to the present disclosure has a hollow region, so that the interference of the electromagnetic wave signals generated by the radiation elements for other frequency bands (e.g. the radiation element 220 for high frequency band) is reduced, and thus the dual-polarized radiation element 210 proposed according to the present disclosure is more friendly to system integration, and the radiation performance of the integrated multi-band radiation element will be better than that of the radiation element in the prior art. In addition, the dual-polarized radiation unit 210 according to the present disclosure has a simple and convenient manufacturing process because its central portion is dc-conducted, and the dual-polarized radiation unit 210 according to the present disclosure has a better product consistency and radiation performance because it can be integrally constructed.

The above description is only an alternative embodiment of the present disclosure and is not intended to limit the embodiment of the present disclosure, and various modifications and variations of the embodiment of the present disclosure may occur to those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the embodiments of the present disclosure should be included in the scope of protection of the embodiments of the present disclosure.

Although embodiments of the present disclosure have been described with reference to several particular embodiments, it should be understood that embodiments of the present disclosure are not limited to the particular embodiments disclosed. The embodiments of the disclosure are intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A dual polarized radiating element for an antenna, said dual polarized radiating element comprising:

four dipoles, wherein radiating arms of the four dipoles are planar structures and are symmetrical about two mutually perpendicular lines that divide the radiating element equally into four regions, and central portions of the four regions are in direct current conduction,

and wherein each of the four regions has a hollow region.

2. A dual polarized radiating element according to claim 1, wherein a first edge of the dual polarized radiating element is perpendicular to a respective one of the two mutually perpendicular lines, wherein the first edge is an edge that intersects the respective line.

3. A dual polarized radiating element according to claim 2, wherein the dual polarized radiating element has an octagonal shape.

4. The dual polarized radiating element of claim 1, further comprising:

four slits located at respective abutments of two adjacent ones of the four regions.

5. The dual polarized radiating element of claim 4, further comprising:

four feed lines associated with the four slots, and each of the four feed lines extending from a middle region of the dual-polarized radiating element to a feed point of the slot associated therewith, wherein a length of the feed lines is associated with a matching impedance.

6. The dual polarized radiating element of claim 5, further comprising:

a common mode choke circuit configured to be disposed near the feed point and associated with one of the four slots.

7. The dual polarized radiating element of claim 6, wherein the common mode choke circuit further comprises a first track and a second track, wherein the first track and the second track are configured in the form of inductive coils parallel to each other on both sides of the radiating arm, and wherein the first track and the second track are equal in electrical length and the direction of coil winding of the first track and the second track is uniform.

8. The dual polarized radiating element of claim 1, further comprising:

a shunt filter configured as a wire extending inward from an edge of the hollow region.

9. The dual polarized radiating element of claim 8, wherein the parallel filters are configured as open lines.

10. The dual polarized radiating element of claim 1, further comprising:

an inductive element extending from an edge of the hollow region away from a central region of the dual polarized radiating elements towards the central region.

11. An antenna, characterized in that the antenna comprises:

at least one dual polarized radiating element according to any one of claims 1 to 10; and

a radiating element matching circuit.

12. An antenna system, characterized in that the antenna system comprises:

the antenna of claim 11; and

at least one second antenna, wherein the operating frequency band of the at least one second antenna is higher than the operating frequency band of the antenna.

13. The antenna system of claim 12, wherein the antenna is interleaved with the second antenna.

14. The antenna system according to claim 13, wherein the number of columns of antennas and the number of columns of the second antenna are equal or twice the number of columns of antennas.